The present invention relates to an environmental abnormality detecting apparatus for detecting an analog signal representing an abnormality in smoke, heat, gas or the like and producing an alarm.
An accumulator type fire detector is one type of conventional smoke detector for detecting a fire which has been proposed wherein analog smoke signals are accumulated in an accumulator and the fire detector is started when an accumulation level exceeds a predetermined level so as to improve reliability. However, according to this conventional fire detector, even if a level of the analog signal is extremely high, it takes a long period of time to operate the fire detector, resulting in inconvenience. An example of such a conventional accumulator type fire detector is described in U.S. Pat. No. 3,872,449, incorporated herein by reference.